JP2003032908A - Capacitor battery pack, control method and controller thereof, and automotive storage system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of variations of a charging condition in respective electric double-layer capacitors for a capacitor battery pack. SOLUTION: This capacitor battery pack, the control method and controller thereof, and the automotive storage system are capable of charging and substantially uniformly with the plurality of electric double-layer capacitors 11 connected in series, and discharge the electric double-layer capacitor 11 with at high charging conditions among the electric double-layer capacitors.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to charge / discharge control of a chargeable / dischargeable battery pack in which electric double layer capacitors are connected in series, and particularly to a 12V automobile, 42V for the purpose of improving energy efficiency. The present invention relates to charging / discharging control of an electric double layer capacitor as a power source used for electric power storage such as automobiles, electric vehicles, hybrid vehicles, and load leveling.

[0002]

2. Description of the Related Art As a conventional electric storage device for automobiles, 1
2V vehicles are equipped with lead battery vehicles, and hybrid vehicles are equipped with nickel-hydrogen storage batteries. In addition, lead batteries, nickel-cadmium batteries, and the like are used for power storage.

Electric storage devices such as lead storage batteries, nickel-cadmium batteries, and nickel-hydrogen batteries used in conventional electric storage devices are chemical batteries that utilize chemical reactions, and have a reaction rate with respect to charge and discharge that is electronically conductive. Very slow against high output, the reversibility of the reaction itself decreases with charge and discharge cycles, and
It has a shorter life than electronic parts.

[0004]

DISCLOSURE OF THE INVENTION <A> The present invention is to eliminate variations in the state of charge in each electric double layer capacitor of a battery pack. <B> Further, the present invention is to miniaturize the discharge circuit of the electric double layer capacitor.

More specifically, according to the present invention, a capacitor using an electric double layer only adsorbs / desorbs ions upon charging / discharging, and its reaction rate is very fast, and theoretically its reversibility. Is not lost, which is advantageous for applications requiring high output and long life. However, when an electric double layer capacitor is used as a battery pack in which a plurality of electric double layer capacitors are connected in series, the electric double layer capacitors are unevenly charged, and the electric double layer capacitors are overcharged. May invite you. Therefore, the present invention is to equalize the state of charge of a plurality of electric double layer capacitors connected in series.

[0006]

In order to solve the above problems, the present invention relates to a chargeable / dischargeable battery pack in which a plurality of electric double layer capacitors are connected in series, and the charge state of each electric double layer capacitor is changed. In order to make the electric double layer capacitors substantially even, the electric double layer capacitors having a high charge state are discharged, or in the capacitor assembled battery, the charge state of the electric double layer capacitors is , A capacitor assembled battery characterized by being calculated by the voltage of the electric double layer capacitor,
Alternatively, in the capacitor battery pack, when a series circuit of an adjustment resistor and an electric switch is connected in parallel with each electric double layer capacitor and the electric switch is turned on, a current flowing through the adjustment resistor is allowed by the electric double layer capacitor. Or less, the capacitor assembled battery, or in the capacitor assembled battery, an adjusting resistor that is connected in parallel with each electric double layer capacitor and adjusts the state of charge of each electric double layer capacitor. Is larger than the value obtained by dividing the rated voltage or withstand voltage of the electric double layer capacitor by the upper limit current of the wiring material / part, or in the capacitor assembled battery, or The difference between the state of charge of the electric double layer capacitor with the highest state of charge and the average value of the state of charge of other electric double layer capacitors is When the threshold value is equal to or higher than a predetermined value, the highest electric double layer capacitor is discharged, and when the threshold value is equal to or lower than the lower limit value, the highest electric double layer capacitor is stopped from being discharged, In the capacitor assembled battery, when the difference between the charge state of the electric double layer capacitor having the highest charge state and the charge state of the electric double layer capacitor having the lowest charge state among the electric double layer capacitors is equal to or more than the upper limit predetermined value, the A high-capacity battery pack or a plurality of electric double-layer capacitors connected in series, which discharges a high electric double-layer capacitor, and stops discharging the highest electric double-layer capacitor when the lower limit value is not exceeded. In the control method of the chargeable / dischargeable battery pack, the electric double layer capacitors are controlled so that the electric charge is approximately equal. Control method for a capacitor battery pack, which comprises discharging a high electric double layer capacitor of the charge state in the layer capacitor, or,
A chargeable / dischargeable battery pack in which a plurality of electric double layer capacitors are connected in series, a voltmeter for measuring the voltage of each electric double layer capacitor, and an adjusting resistor connected in parallel with each electric double layer capacitor. A series circuit with an electric switch and an electric switch control device for turning on the electric switch to discharge the electric double layer capacitors are provided, and the electric double layer capacitors are arranged so that the charge states of the electric double layer capacitors are substantially equalized. Among them, a capacitor assembled battery control device characterized by turning on an electric switch of an electric double layer capacitor having a high charge state, or a chargeable / dischargeable vehicle for which a plurality of electric double layer capacitors are connected in series In the power storage system, the charging state of each electric double layer capacitor is set to a high level so that the charging state of each electric double layer capacitor is almost equalized. In power storage system for a motor vehicle, characterized in that discharging the electric double layer capacitor.

More specifically, in an assembled battery in which a plurality of electric double layer capacitor cells or a plurality of capacitor modules in which a plurality of two or more capacitor cells are connected in parallel are connected in series, each electric double layer capacitor C as shown in FIG. _In parallel with _i , the adjusting resistor R _i (Ω) and the electric switch SW _i
Connect.

At this time, the adjusting resistor R _i has the rated voltage or withstand voltage of the electric double layer capacitor C _i connected in parallel as V _i (V), the adjusting resistor R _i (Ω) and the adjusting resistor in series. When the electric current value that the electric switch SW _i and the copper wire connected to the terminal can withstand is I ₀ (A), the adjustment resistance R _i is V
Select _i / I ₀ (Ω) or more. As a result, the adjustment resistor and the electric switch portion can be downsized.

In this system, by turning on and off the electric switch of the adjusting resistor Ri in any of the charging state, the resting state and the discharging state, only the electric double layer capacitor connected in parallel to the adjusting resistor is discharged. Sir,
It is possible to reduce the state of charge.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

<A> Capacitor Battery Control Device The capacitor battery control device 2 prevents the charging states of the plurality of electric double layer capacitors 11 forming the battery pack 1 from varying, and prevents overcharging. To prevent. For that purpose, the capacitor assembled battery control device 2 measures the voltage of each electric double layer capacitor 11, and the switch control device 21 causes the electric double layer capacitor 1 whose charge state is higher than that of the other electric double layer capacitors 11.
No. 1 is discharge controlled.

<B> Capacitor Assembly Battery The capacitor assembly battery 1 is constructed by connecting the electric double layer capacitors 11 in series. The electric double layer capacitor 11 refers to an electric double layer capacitor cell or a capacitor module in which electric double layer capacitor cells are connected in parallel.

<C> Electric Double Layer Capacitor Cell The electric double layer capacitor cell is formed by disposing an ion conductive material between a pair of electrode structures, and comprises a high surface area material and an ion conductive material in the electrode structure. An electric double layer is formed with the electrolyte. The high surface area material is a powdery high surface area material capable of attracting a large number of ions to the surface. Particularly, a carbon material is subjected to a steam activation treatment method, molten KOH.
Activated carbon activated by an activation treatment method or the like is preferable. Examples of the activated carbon include coconut husk activated carbon, phenol activated carbon, petroleum coke activated carbon, polyacene and the like, and it is possible to use one of these alone or in combination of two or more. Of these, phenol-based activated carbon, petroleum coke-based activated carbon, and polyacene are preferable for achieving a large capacitance.

<D> Measurement of state of charge of electric double layer capacitor The state of charge of the electric double layer capacitor 11 is a state of the amount of electric charge accumulated in the electric double layer capacitor 11, for example, a voltmeter 22 or an ammeter. Can be measured. In the case of the voltmeter 22, the state of charge can be determined by measuring the voltage of the electric double layer capacitor. The voltmeter 22 is connected between the electric double layer capacitors, for example. The measured value is sent to the switch control device 21 via the voltage measurement line 23.

<E> Adjustment resistance The adjustment resistance 12 is a resistance for adjusting the charging state of the electric double layer capacitor 11, and the electricity charged in the electric double layer capacitor 11 can be discharged through this resistance. it can. The adjustment resistor 12 is connected in parallel with the electric double layer capacitor 11, for example. The adjustment resistor R _i is a rated voltage or withstand voltage of the electric double layer capacitors C _i connected in parallel, V _i (V), the adjustment resistor R _i (Ω), and an electric switch connected in series to the adjustment resistor. When the current value that SW _i and the copper wire can withstand is I ₀ (A), the adjustment resistance R _i
Is selected to be V _i / I ₀ (Ω) or more. by this,
The adjustment resistor 12 and the electric switch 13 can be downsized.

<F> Electric Switch The electric switch 13 is a switching means for discharging the electricity charged in the electric double layer capacitor 11 through the adjusting resistor 12, and is connected in series to the adjusting resistor 12, for example. To be done. The electric switch 13 is controlled by the switch control device 21 to control opening / closing (on,
OFF control). As the electric switch 13, a relay device, a thyristor or the like can be used.

<G> Switch control device The switch control device 21 includes the electric double layer capacitors 11
Examine the voltage V ₁ ~V _n, select the electric double layer capacitor 11 having high charge state, via the switch control line 24, it is charged to turn on the electric switch 13 of the high electric double layer capacitor of the charge state When the electric charge is discharged and the state of charge becomes almost equal to that of the other electric double layer capacitor, the electric switch 13 is turned off to turn on the electric double layer capacitor 1.
1 can control the state of charge.

The switch control device 21 turns on the electric switch 13 of the adjusting resistor Ri regardless of whether the electric double layer capacitor 11 is in a charged state, a rest state, or a discharged state.
By performing the off control, only the electric double layer capacitor connected in parallel to the adjusting resistor 12 is discharged, and the state of charge can be reduced.

<H> Concrete Example of Capacitor Assembled Battery As an example, the capacitor assembled battery 1 has 17 electric double layer capacitor cells 11 having a rated electrostatic capacity of 4,000 F and a rated voltage of 2.47 V. Use it to connect it in series. Each electric double layer capacitor cell 11 is connected in parallel with a 2.47 ohm resistor and an electric switch 13 with a current of 1
A circuit material as shown in FIG. The electric switch 13 is controlled by a switch control device 21 having a voltage detection / arithmetic function and capable of turning on / off an electric switch.

<I> Vehicle Energy Storage System An application example of the capacitor assembled battery 1 is an automobile energy storage system. Power storage systems for automobiles are 12V automobiles, 4
A power storage system for a vehicle such as a 2V vehicle, an electric vehicle, or a hybrid vehicle, including a capacitor assembled battery 1 obtained by combining electric double layer capacitor cells, and at least by charging from a generator A and regenerative charging by braking. Charging / discharging such as discharging by starting the charger B and the engine starter D or discharging by the other load E can be performed. That is, the capacitor assembled battery 1 can be charged and discharged with one type or with a plurality of types. With this configuration, it is possible to satisfy the conditions necessary as a power source for automobiles, for example, the conditions of voltage and current for starting the engine and other electric devices, and the conditions of regenerative charging by charging from a generator or braking. .

The procedure for making the charged state of the electric double layer capacitor substantially uniform will be described below.

<B> Determination of Charge State of Electric Double Layer Capacitor According to the control flow of FIG. 3, the voltage V _i (V) of each electric double layer capacitor C _i is measured during charging / discharging operation (S11),
Rated voltage or withstand voltage V _{0 of the} electric double layer capacitor 11
The state of charge SOC _i (%) is changed to SOC by (V).
_It is calculated as _i (%) = V _i (V) / V ₀ (V) × 100 (S12). Here, each electric double layer capacitor C _i
You can know the charge status of.

Next, the SOC_iOut of the
I of the electric double layer capacitor_kTosu
It C_iVariation ΔSOC_i(%) Maximum charge status
Electric double layer capacitor cell C_kState of charge SOC
_kAnd the average value of the state of charge of other capacitor cells,
That is, ΔSOC_i(%) = SOC_k(%)-(ΣSOC
_k-SOC_k) / (N-1) is calculated (S13).

<B> Electric Double Layer Capacitor Discharge Control When this variation ΔSOC _i (%) is less than or equal to the threshold value A (%), for example, 30% or less (S14), the electrical switch SW _k is turned on (otherwise). The SW _i is turned off) (S15). State of charge SO of electric double layer capacitor C _k
The voltage V _i of each electric double layer capacitor C _i is measured and the state of charge SOC _i is calculated without updating whether or not C _k is the maximum, and even if the electric double layer capacitor C _k is discharged and the state of charge SOC is changed. _{Even if k} is not the maximum value, k
ΔSOC _i is calculated for (S16). ΔSOC _i
Is below an arbitrary value B (%) less than A (%) (S
17), SW _k is turned off (S18), the control flow is returned to the initial stage, and the detection and control are repeated.

<C> Other discharge control of electric double layer capacitor
You SOC according to the control flow of FIG._iOf the highest charge status
I is determined and the electric double layer capacitor is_kWhen
And determine the minimum charge state i,
To C_l(S21). In addition, the control flow of FIG.
The same processes as those in the control flow of FIG. 3 are designated by the same reference numerals. C
_iVariation ΔSOC_i(%) Is the maximum state of charge SO
C_kAnd minimum SOC_lThe difference, that is, ΔSOC_i(%)
= SOC _k(%)-SOC_lIs calculated as (S2
1).

This variation ΔSOC _i (%) is the threshold value A.
When (%) or less, for example, 30% or less (S14), the electric switch SW _k is turned on (the other SW _i are turned off) (S15). Measuring the voltage V _i of each electric double layer capacitor C _i charge state SOC _k of the electric double layer capacitor C _k is without any update if it is a maximum state of charge SO
C _i and ΔSOC _i are calculated (S16). Even if the electric double layer capacitor C _k is discharged and the state of charge SOC _k is not the maximum value, ΔSOC calculated for k
_{When i} becomes an arbitrary value B (%) or less less than A (%) (S17), SW _k is turned off (S18), the control flow is returned to the initial stage, and the detection and control are repeated.

[0027]

According to the present invention, the following effects can be obtained. <A> The present invention can eliminate the variation in the state of charge in each electric double layer capacitor of the battery pack. <B> Further, according to the present invention, the discharge circuit of the electric double layer capacitor can be downsized.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an automobile power storage system including a capacitor assembled battery.

FIG. 2 is an explanatory diagram of a capacitor assembled battery control device.

FIG. 3 is a flow chart for preventing variation in charge state of electric double layer capacitors.

FIG. 4 is a flowchart for preventing other variations in the charging state of the electric double layer capacitor.

[Explanation of symbols]

1 ... capacitor assembled battery 11 ... electric double layer capacitor _C 1 _-C n 12 ... adjusting resistor _R 1 _{to R} n 13 · electrical switch _SW 1 _{to SW} n 2 ... capacitor battery pack controller 21 ..Switch control device 22..Voltmeter 23..Voltage measurement line 24..Switch control line A ... Generator B ... Charger D by regenerative charging D ... Engine starter E ... Other than engine starter Load S _A: Generator changeover switch S _B: Charger changeover switch S _D: Engine starter A contact switch S _E : Negative changeover switch other than engine starter

Continued front page    F-term (reference) 5G003 AA07 BA03 CA11 CB08 CC02                       DA07 FA06                 5H115 PA08 PA15 PG04 PI16 PO17                       PU01 SE06 TI01 TI05 TI06                       TI09 TR19 TU01 TU16 TU17                       UI35

Claims (9)

[Claims] 1. In a chargeable / dischargeable battery pack in which a plurality of electric double layer capacitors are connected in series, the electric double layer capacitors are made to have a substantially equal charge state.
A capacitor assembled battery, which discharges an electric double layer capacitor having a high charge state among the electric double layer capacitors. 2. The capacitor assembled battery according to claim 1, wherein the state of charge of the electric double layer capacitor is calculated by the voltage of the electric double layer capacitor. 3. The capacitor assembled battery according to claim 1, wherein a series circuit of an adjusting resistor and an electric switch is connected in parallel with each electric double layer capacitor, and when the electric switch is turned on, the electric current flows to the adjusting resistor. An assembled battery of capacitors, characterized in that an electric current is set to be equal to or less than an allowable value of an electric double layer capacitor. 4. The capacitor assembled battery according to claim 1, wherein the adjustment resistor that is connected in parallel with each electric double layer capacitor and adjusts the state of charge of each electric double layer capacitor has a rating of the electric double layer capacitor. A capacitor assembled battery characterized by having a voltage or withstand voltage higher than a value obtained by dividing an upper limit current of a wiring material or a component. 5. The capacitor assembled battery according to claim 1, wherein a charging state of an electric double layer capacitor having the highest charging state among electric double layer capacitors and an average value of charging states of other electric double layer capacitors. If the difference exceeds the upper limit specified value,
A capacitor assembled battery, wherein the highest electric double layer capacitor is discharged, and when the lower limit of a predetermined value or less is reached, the highest electric double layer capacitor is stopped. 6. The capacitor assembled battery according to claim 1, wherein an electric double layer capacitor having the highest charging state among the electric double layer capacitors and a charging state of the electric double layer capacitor having the lowest charging state are provided. When the difference is equal to or higher than a predetermined upper limit value, the highest electric double layer capacitor is discharged, and when the difference is equal to or lower than the lower limit predetermined value, discharging of the highest electric double layer capacitor is stopped. 7. A method of controlling a chargeable / dischargeable battery pack in which a plurality of electric double layer capacitors are connected in series, wherein the electric double layer capacitors are arranged so that the charged states of the electric double layer capacitors are substantially equal. A method for controlling a capacitor assembled battery, which comprises discharging an electric double layer capacitor having a high charge state. 8. A battery pack comprising a plurality of electric double layer capacitors connected in series, capable of charging and discharging, a voltmeter for measuring the voltage of each electric double layer capacitor, and connected in parallel with each electric double layer capacitor. A series circuit of an adjusting resistor and an electric switch, and an electric switch control device for turning on the electric switch to discharge the electric double layer capacitor,
A capacitor assembled battery control device characterized by turning on an electric switch of an electric double layer capacitor having a high charging state among the electric double layer capacitors to discharge so that the electric charge states of the respective electric double layer capacitors are substantially equalized. . 9. An electric storage system for a vehicle, comprising a plurality of electric double layer capacitors connected in series, which can be charged and discharged, so that the electric double layer capacitors have a substantially equal charging state. An electric storage system for a vehicle, which discharges an electric double layer capacitor having a high state of charge.